Reversible pitch propeller



May 25, 1954 M. J. KELSON, SR 2,679,299

REVERSIBLE PITCH PROPELLER Filed May 6, 1950 INVENTOR.

Patented May 25, 1954 UNITED STATES @ATENT OFFICE REVERSIBLE PITCH PROPELLER Malcolm J. Kelson, Sn, Detroit, Mich. Application May 6, 1950, Serial No. 160,411

1 Claim.

This application is a continuation-in-part of application Serial No. 63,509, filed December 4, 1948, and now abandoned.

This invention relates to adjustable or reversible pitch propellers, more particularly for power boats, and has for its object to provide a simply operable and durable arrangement of parts wherein the propeller blades are supported on the propeller shaft in a manner admitting of easy adjustment and setting as to angle; and wherein the housing enclosing part of the adjusting mechanism is relieved to a great extent from actual support of the propeller blades whereby undue wear of the blade bearings is prevented and the development of looseness or leakage in or about such bearings is minimized.

A further object is to provide inner and outer co-axial propeller shaft members at least one of which is geared to the propeller blades in such manner that relative rotation of said members will efiect pitch adjustment of the said blades, and a reciprocal sleeve interposed between said inner and outer shaft members, said sleeve having a splined engagement with both of said members, at least one of which splines is of a screw type, whereby reciprocation of the sleeve will cause relative rotation of said shaft members one to another.

A further object of the said invention is to provide, by the application of a pair of bevel gears mounted respectively on the driving sleeve and shaft, and both gears in mesh with bevel gearing carried by each of the propeller blades, with at least one of said first mentioned gears being keyed or similarly secured to the shaft (or to the sleeve, as the case may be) whereby both of firstmentioned gears will cooperate in the distribution of forces and shock between the gears of the propeller blades, resulting in a smooth-running and low-vibration propeller assembly characterized by high shock resistance.

Still further objects or advantages subsidiary to or resulting from the aforesaid objects, or resulting from the construction or operation of the invention as it may be carried into efiect, will become apparent as the said invention is hereinafter further described.

In carrying the said invention into effect, I may adopt the novel construction and arrangement of parts hereinafter described, by way of example, having reference to the accompanying drawing, wherein:

Figure 1 is a sectional elevation of a. preferred embodiment of the invention;

Figure 2 is a transverse section of the same,

2 taken on a plane indicated by the line 22 in Figure 1;

Figure 3 is a similar view to Figure 1 of a modified embodiment of the invention; and

Figure l is a transverse section of the same, taken on a plane indicated by the line 4-4 in Figure 3.

Similar characters of reference indicate similar parts in the several figures of the drawing.

Referring first to Figures 1 and 2, It indicates a power shaft suitably coupled as at l l to a propeller shaft member l2. extends through a tubular outlet member [3 and between these members is arranged a reciprocal sleeve I a.

That end of the sleeve M which enters the tubular member I3 is internally grooved as at E5 to mesh with splines IS on the shaft member 12, and the outer shaft member I3 is internally grooved as at I l to mesh with splines I8, formed on the inner end portion of the said sleeve M. Both the splines 1H; and splines I8, however, in this example, are of screw type and of opposite hand so that it will be readily seen that reciprocation of the sleeve M in one or other direction will effect corresponding and relative rotation of the members l3 and M in opposite directions, notwithstanding the fact that both members may be actually rotating in a single direction in the driving of a propeller as a whole.

is indicates any suitable thrust collar or coupling through which the reciprocation of the sleeve Id may be effected.

The propeller blades 20 are shown as having their spindles 2| extending through and into the housing 22 and mounted for support and rotation on the arms 23 of a spider 24; which spider, in this example, is freely rotatable on the shaft member l2.

Keyed to the end of the said shaft member l2, within the housing 22, is a bevel gear 25, and a second bevel gear 26 within the said housing is keyed to the end of the outer tubular shaft member l3. These two gears 25 and 26 mesh at diametrically opposite points with bevel gears 21 carried by the spindles 2! of the propeller blades. Thus the relative rotation of these gears 25 and 28 in opposite directions, as a result of such rotation of the shaft members I2 and I3, upon reciprocation of the sleeve 14 will effect pitch variation of the propeller blades as will be obvious.

It will be observed that the gears 25 and 26 not only serve the purpose of controlling pitch variation of the propeller blades, but are directly This shaft member l2' 3 charged with the rotation of the propeller as a whole. In other words, the housing 22 merely travels with the propeller as a whole and does not need to be actually keyed in any way to the shaft member l3, so that excessive strains and pressures of the spindles 2| of the propeller blades on the housing are eliminated. Consequently, any type of bearing which may be utilized in the housing structure about the spindles of the propeller blades will be subjected to very little wear and will provide great freedom of movement for pitch adjustment of the blades Without developing looseness of undesirable leakages, whereby oil or grease retention-inthe housing may be maintained over a long period of time and vibration of the propeller reduced- 7 to a minimum.

In the modified form shown in Figures 3 and shaft member H3) simply having key-ways 28. formed internally thereof in which slidestraight keys 29 formed or mounted on the-sleeve M; and in this arrangement only the bevel gear 26 is keyed to the ends of the shaft I3 to drive the propeller blade gears!!! while the bevel gear 31 is freely rotatable about the shaft l2 and forms a coupling idler between thesaid gear 21. In this case the spider 2-4 is keyed to the-shaft member 12, as at 30, and here-again, as in the first example, the housing 22 is not charged with the driving of the propeller as a whole, the driving forces being merely through the Spider 24 and to some extent through the said gear 21. The steadying and even distribution of shock between the tworgears 2.! (and so between the propeller blades) is supplemented by the idler gear3l.

This invention may be developed within the scope of the following claims without departin from the construction or operation of the said invention and it is desired that the specification and drawing be read as being merely illustrative of a practical embodiment of the invention, and not in a strictly limiting sense.

What I claim is:

In an adjustable pitch marine propeller mechanisrn, a housing, propeller; blades having spin dles extending into saidhousing, inner and outer co-axial shafts extending into said housing, a spider freely mounted on said inner shaft, said spidenhaving'arms on which said spindles are mounted for support and rotation, sun bevel gears carried' by said shafts, lanet bevel gears meshed withisaid sun gears and carried by said spindles, a reciprocal sleeve between said inner and outer shafts, said sleeve having right hand splined engagement with, one of said shafts and left hand splined engagement with the other of said shafts and means for adjustably reciproeating said sleeve.

References Cited in the file of this patent UNITED STATES'PA'IENTS Number Name Date 605,322 Winand June 23, 1893 FOREIGN PATENTS Number Country. Date 99;775 Sweden July 4, 1898 180,248 Switzerland Jan. 2, 1936 337,4i82 France Feb. 20, 1904 544,419 France a June 21, 1922 408,847 Italy Sept. 1946 

